Check out our Shared Ban List for a list of scammers and people abusing others' kindness in various subreddits. Block and do not gift to these users. To view users banned before 2014 click 2012-2013 which can be found at the bottom of the page. Here's an image to show you where to look in case you're having trouble finding it.

Our Givers/Receivers list is public, so anyone is free to see what items have been gifted and to whom.

I don't mean to put you down, you're very generous for offering your code. THQ, however, is giving away Metro 2033 for free. I think, if you don't already have the game, you should keep it and instead link everyone to THQ's giveaway site here. It only takes a "like" on Facebook. It'd be best, in my opinion, if you save your code for giving away until after December 16th, so that the giveaway can be fully enjoyed by everyone.